The invention relates to a receiver having a frequency synthesising circuit comprising a reference oscillator, said receiver also having a radio-frequency section, a local oscillator and an intermediate frequency section, the local oscillator being tunable by means of the reference oscillator to a frequency which adjusts the intermediate frequency to a standard intermediate frequency.
Funkschau 1976 volume 20, pages 839-842, discloses a receiver of the type defined above. In that receiver the frequency of the local oscillator is coupled to the frequency of an extremely stable reference oscillator, so that a very constant oscillator tuning is obtained. However, it is not possible, as is characteristic of receivers without frequency synthesising, to compensate for any variation in the tuning of the intermediate frequency section by causing compensating frequency variations of the local oscillator to be produced.
It would be possible to perform such a correction by means of an automatic frequency control circuit acting on a received signal. However, there is the risk that said circuit locks-in to an unwanted transmitter.